The patient with leukemia has acute disseminated intravascular coagulation (DIC) and is bleeding. What diagnostic finding supports this diagnosis?

A. Reduced fibrin split products (FSPs): In DIC, fibrin is excessively formed and subsequently broken down, leading to increased, not reduced, fibrin split products. A reduction in FSPs would not support the diagnosis and may indicate a laboratory error or absence of active clot breakdown. B. Elevated fibrinogen: Fibrinogen is typically consumed during the coagulation process in DIC, leading to decreased levels rather than elevated. Low fibrinogen contributes to bleeding tendencies observed in patients with DIC. C. Reduced prothrombin time (PT): In DIC, coagulation factors are depleted, resulting in a prolonged PT. A shortened PT is not consistent with consumptive coagulopathy and does not support the diagnosis. D. Elevated D-dimer: D-dimer is a degradation product of cross-linked fibrin and is markedly elevated in DIC due to widespread clot formation and subsequent fibrinolysis. Elevated D-dimer is a key laboratory finding supporting the presence of acute DIC and correlates with active intravascular coagulation and bleeding risk.